JPS5926957A - Method for producing cured calcium silicate hydrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cured calcium silicate hydrate.

Conventionally, many hardened calcium silicate hydrates containing tonokumolite and/or dinotraite as main minerals have been produced by subjecting a mixture of silicic raw materials and calcareous raw materials to a hydrothermal reaction under high temperature and pressure. These calcium silicate hydrates are not only used as plastic fillers, adsorbents, catalysts, etc., but also the cured products containing calcium silicate hydrates as the main component have excellent strength, heat resistance, and The following products are manufactured. For example, (1) lightweight heat insulating material, (2) fireproof covering ff1U, (31 partition material, (
4) Interior and exterior wall materials, (5) A, LC (autoclaved transposed aerated concrete), (6) ball-filled bricks, etc.

The lightweight heat insulating material (1) and the partition material (3), fireproof covering material (2), are mainly made of silicic acid raw materials and calcareous raw materials, and if necessary, asbestos, clay, etc. are added as reinforcing materials. Add water to the mixture to make a slurry, pour this slurry into a mold, mold it, perform a hydrothermal reaction in an autoclave, then remove the mold and dry it. After pouring this gel-like material into a mold, the resulting molded product is subjected to a hydrothermal reaction in an autoclave, or a slurry of calcareous raw materials and silicic raw materials is stirred in an autoclave. First, a slurry containing crystals of a self-hardening calcium silicate aquarium is obtained through a hydrothermal reaction, and the slurry is obtained either as it is or by adding a reinforcing material and forming and drying it.

Among (4), for the external wall material, in addition to the same methods as those for products (1) to (3), extrusion molding or paper forming may be used. (5) ALC consists of siliceous raw materials such as silica stone, cement,
By adding air bubbles made from various additives and a small amount of foaming agent, foaming agent, surfactant, etc. to calcareous raw materials such as quicklime and granulated slag, pouring into a mold and leaving it for a while. It is produced by obtaining a semi-plastic material containing bubbles, cutting it with steel wire, etc., and then subjecting it to a hydrothermal reaction in an autoclave.

The ball-filled brick (6) is produced by adding water to a silicate raw material and a calcareous raw material to form a slurry, molding the slurry under pressure, and then subjecting it to a hydrothermal reaction in an autoclave.

As mentioned above, although there are some differences in the manufacturing method of lightweight insulation materials, fireproof covering materials, partition materials, interior and exterior wall materials, ALC, and ball-filled bricks, all methods use silicic and calcareous raw materials. A slurry made by adding water to the main raw material is subjected to a hydrothermal reaction under high temperature, high pressure, and saturated steam pressure in an autoclave to produce calcium silicate hydrate minerals such as tono9molite and xonotrite. It is recognized that the strength and thermal stability of the cured product can be obtained by using water supplies. However, producing these calcium silicate hydrate minerals requires a very long-term reaction, and although it varies depending on the product, it usually requires a high-temperature, high-pressure hydrothermal reaction for at least 10 hours. It is said that

Therefore, the present inventors conducted intensive research to improve the drawbacks of the above-mentioned technology, and arrived at the present invention.

According to the present invention, if a lithium-containing substance is added to a silicate raw material and a calcareous raw material, water is added, and a hydrothermal reaction is performed, the time is reduced compared to the case where tobermorite or xonotlite, which are calcium silicate hydrates, is not added. It also forms under low temperature and low pressure conditions. Furthermore, if the reaction is carried out under the same conditions, a cured product with higher strength can be obtained than that without addition.

The present invention will be specifically explained below.

The present invention provides a method for producing a cured hydrate of calcium silicate, characterized in that the reaction is carried out in the presence of a lithium-containing substance when a calcareous raw material, a silicate raw material, and water are subjected to a hydrothermal reaction under high-temperature, high-pressure saturated steam. It is.

The lithium-containing substances used in the present invention include lithium hydroxide, various lithium salts, minerals with a lithium content of 3% or more in terms of L120, and the like. For example, lithium hydroxide,
The chlorides of lithium include lithium chloride, lithium fluoride, lithium bromide, lithium iodide, salts of lithium hydroxide and mineral acids, such as lithium nitrate, lithium sulfate, lithium carbonate, and lithium phosphate. , lithium thiocyanate, and carmenates such as lithium acetate and lithium stearate. In addition to these lithium salts, examples include minerals having a lithium content of 3% or more in terms of L120, such as spodumene (lebidolite), Chinwald mica, ambrigoite (petalite), and spodumene (subodumene). The amount of addition of these lithium-containing substances is 0.10 of the total of siliceous raw materials and calcareous raw materials, when the lithium content in the lithium-containing substances is converted to Li2O.
It is desirable to add up to 15.0%. Particularly undesirable 0
．． It is preferable to add 15 to 10.0%. No substantial increase in effect was observed even when added above this level, and no effect was observed when added below this level.

The silicic acid raw material used in the present invention may be any material used in ordinary hydrothermal reactions. For example, silica, diatomaceous earth, china clay, zeolite, fly ash, ferron recondust, silate slag and other types of silicate materials and materials with a 5i02 content of 40% or more can be used. Also,
As the calcareous raw material, portolan P cement, alumina cement, quicklime, slaked lime, slag, etc. can be used.

Calcium silicate hydrate (Ca
OS log H20 minerals) include xonotrite (
6CaO・6SiO2・H2C); hoshagite (4
CaOa 3Si02 #H2C); ) /'molite (5CaO・6SIOi e5H2O); gyrolite (8Ca(112SiO1・9)I, 01
etc. can be mentioned. The raw material composition (Cao/Stow) molar ratio must be selected depending on these target minerals. In other words, if gyrolite is to be produced, the CaO/SiO2 molar ratio is preferably 0.3 to 07. If you want to generate tobermorite, 0.6~
1.0 is preferable, 0.8 to 1.2 is preferable if zonolite is to be produced, and 10 to 1.5 is preferable if hoschagite is to be produced.

The hydrothermal reaction in the present invention refers to a reaction for producing calcium silicate hydrate minerals at a high temperature and pressure higher than the saturated water vapor pressure of 120°C, and preferably at a temperature of 120°C or higher and 250°C or lower. The reaction conditions must be appropriately determined depending on the mineral of interest; for example, when the purpose is to produce tonokumorite, the saturated water vapor pressure is 160°C to 200°C, and when the aim is to produce xonotrite, the saturated water vapor pressure is 180°C to 200°C. It is preferable to carry out under saturated steam pressure of 220°C. Mineral crystals are formed in a hydrothermal reaction that usually takes 2 to 6 hours, and can be produced in about half the reaction time of conventional methods. In addition, since the production of calcium silicate aqueous products is promoted, it has been found that when a lithium-containing substance is added in the same moxibustion reaction, the strength of the cured product is increased.

Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited to these Examples.

Examples 1 to 5 Specially selected slaked lime (manufactured by Yoshizawa Lime) was used as the calcareous raw material, and Chiyane silica was used as the silicate raw material, each of which was ground to a total of 170 mesh (8871), and CaO/5iO2f molar ratio) 105, and a predetermined amount of amosite asbestos by weight of 5 weight of total solids, e-cent, and lithium-containing material are added and mixed. Add 10 times the amount of water to the weight of the total solid content and stir thoroughly to make a uniform slurry. Heat this at 95 to 100°C for 2 hours to create a gel-like substance, which is then filled into a press mold and processed. Pressure dehydrated and molded. The molded product was placed in an autoclave and subjected to hydrothermal reaction for a predetermined period of time.
It was dried at 0°C for 5 hours. The bulk specific gravity of the molded article was 0.35. Table 1 shows the properties of the molded product thus produced.

(Remainder below) Table 1 Results of Examples and Comparative Examples The height was set as 100%. ) Comparative Examples 1-2 Molded bodies were produced in exactly the same manner as in Examples 1-5, except that no lithium-containing substance was added. Examples of its production: Specially selected slaked lime (Yoshizawa lime!) was used as the calcareous raw material, and Shimayane silica stone was used as the silicate raw material.
88μ) Grind and mix thoroughly.

To this, 5 parts of lithium hydroxide was added by external cutting of the total solid content, and the raw material Cab/Si02 molar ratio was blended to 0.95, and water was added in an amount 10 times the total solid content by weight. The mixture was added and stirred to create a slurry. Put this in an autoclave and
6 with stirring at a rotational speed of 45 r, p, m at 00 °C.
After an hour of hydrothermal reaction, the reactants were removed from the autoclave. To this, 5% by weight and 2% by weight of amosite asbestos tocellulose fibers were added by external cutting of the hardness, and after mixing, this was filled into a press mold, dehydrated under pressure, and then dried at 105°C. . The bulk specific gravity of the molded article was 0.36. In addition, the bending strength is 12.8K
>+/*, the residual shrinkage rate after treatment at 100'O<0>C for 2 hours was 1.09cm.

Comparative Example 3 The same procedure as in Example 6 was carried out except that lithium hydroxide was not added, and a molded article having a bulk specific gravity of 0.35 was obtained. The bending strength of this molded body is 7°IKP/m and 7co
In addition, when it was treated at 100°C for 2 hours, it contracted violently and cracked.

Example 7 80 parts by weight of ordinary Portland cement, 20 parts by weight of quicklime, Ukusu silica (powderability 2900 cJ/g-)
parts by weight of tio, 8 parts by weight of lithium sulfate, 150 parts by weight of diwater
Add parts by weight to make slurry. To this was added 1.6 parts by weight of metallic aluminum powder, and the mixture was poured into a formwork provided with reinforcing reinforcing bars. After leaving it for several hours, it becomes semi-plastic and is then cut and shaped with a steel wire.

This was placed in an autoclave and subjected to a hydrothermal reaction for 4 hours under saturated steam pressure at 180°C, resulting in an ALC with an absolute dry specific gravity of 0.51.
was manufactured. The compressive strength of this ALC is 59 K9/d,
The bending strength was 1"t 16 KP/cA.

Comparative Example 4 AI and C were produced in exactly the same manner as in Example 7 except that lithium sulfate was not added. The absolute dry specific gravity of the obtained AL'C was 0.50. Also, the compressive strength is 31Kp/cr
I, the bending strength was 6 to 5'/crI. When X-ray diffraction measurements were performed on the ALC obtained in Example 7 and Comparative Example 4,
In Example 7, the tobermorite peak appeared sharply, whereas in comparison row 4, no tobermorite peak was observed.
Only one broad C8H gel was observed.

Patent applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] 1. A hardened calcium silicate hydrate, characterized in that a calcareous raw material, a silicate raw material, and water are subjected to a hydrothermal reaction under high-temperature, high-pressure saturated steam, and the reaction is carried out in the presence of a lithium-containing substance. Production method 2 The lithium-containing substance is lithium hydroxide, lithium halide, lithium carbonate, lithium nitrate, lithium sulfate, lithium silicate, lithium phosphate, lithium thiocyanate, lithium calzenate, and the lithium content is L i20 Calcium oxide content and silicon oxide content in the mixture of calcareous raw material and silicic raw material. molar ratio of amounts (Ca o/s i
O2 molar ratio) is 0.3 to 1.5%, and the amount of lithium-containing material added is 0.15 to 10% in terms of Li2O, based on the total weight of calcareous raw material and silicic raw material.
．． Manufacturing method 4 according to claim 1, in which the lithium-containing material, other additives, and water are added to the powdered silicate raw material and calcareous raw material to form a slurry, and the slurry is heated under high temperature and high pressure under hydrothermal heat. After performing the reaction to obtain a slurry containing calcium silicate hydrate, a fibrous reinforcing material, etc. is added, and pressure dehydration molding is performed to produce a cured calcium silicate hydrate. Manufacturing method 5 described in Section 5, a lithium-containing substance, a fibrous reinforcing material such as asbestos, a low additive thereof, and water are added to the powdered silicic acid raw material and calcareous raw material to form a slurry, and the slurry is formed as it is or after preliminary reaction. 6. A manufacturing method according to claim 1, which comprises pouring the calcium silicate hydrate into a mold, molding it using a press or the like, and subjecting it to a hydrothermal reaction at high temperature and pressure to produce a cured calcium silicate hydrate.
After adding a lithium-containing substance, other additives, and water to powdered siliceous raw materials and calcareous raw materials, foam produced using a foaming agent such as metal aluminum, a foaming agent, or a surfactant is mixed. The manufacturing method according to claim 1m for manufacturing lightweight cellular concrete containing a calcium silicate aquarium, which involves obtaining a semi-plastic material containing air bubbles, molding the material, and then subjecting it to a hydrothermal reaction under high temperature and pressure.